It is recommended that Backflow Differential Gauges should be tested for accuracy on an annual basis. There are several reasons that support this position:

1. Backflow prevention assemblies are mechanical devices that must be tested on an annual basis to ensure that they are functioning properly. Backflow Differential Gauges are also mechanical devices as well and should be treated in the same manner.​

2.Backflow prevention assemblies have their performance degrade over time based on the water to which they are exposed. Backflow Differential Gauges are exposed to the same conditions as backflow prevention assemblies.

3.Backflow prevention assemblies must be tested by certified backflow technicians to ensure accurate testing. A Backflow Differential Gauge of unknown accuracy would be equivalent to an untrained person testing a backflow prevention assembly.